Fuel-burning system



April 7, 1931. K. A. MAYR 1,799,757

FUEL BURNING SYSTEM Original Filed Dec. 17, 1927 2 Sheets-Sheet latfoznm i April 7 1931. K. A. MA-YR FUEL BURNI-NG S-YSTEM Original FiledDec.

2 Sheets-Sheet 2 Patented Apr. 7, 1931 UNITED STATES PATENT? OFFiCE max.A. Maya, or NEW YORK, N. Y; nssrsnoa 'ro smunns-scnuoxnnrwnnxnAKTIENGESELLSCHAFT, 0F SIEMENSSTADT, NEAR BERLIN, GERMANY, A CORPORA-TION OF GERMANY FUEL-BURNING SYSTEM Original application filed December17, 1927, Serial No. 240,657. Divided and this application filed May 24,1928. Serial No. 280,194.

This invention relates to a control for a fuel burning system and thepresent application constitutes a division of my copending applicationSer. No. 240,657, filed December 1 1927.

The invention has for one of its objects the provision ofa novel controlor safety device for warning an operator of improper operatingconditions and for cutting off the total fuel supply in certainemergencies where otherwise damage would be incurred.

A further ob ect of the present invention resides in the provision ofmeansautomatically brought into operation upon steam attaining anexcessive temperature for shutting off the fuel sup 1y.

A further object of the present invention resides in the provision of asignal and means v for controlling the same to bring it into operationupon the steam which is producedby the burning action of the fuelattaining an excessive temperature.

Other objects and advantages will be hereinafter set forth in theaccompanying specification and claim and shown in the drawings,

which by way of illustration show one and a I preferred embodiment ofthe invention.

In the drawings,

Figure 1 is a diagrammatic view of a steam plant embodying myimprovement.

Fi 2 shows diagrammatically the fuel su plying system with the variouscontrols.

n more detail, referring first to Fig. 1, B

represents a steam generator having a combustion chamber 0 and a draftinducing fan- F. H is a high pressure steam consumer which may exhaustinto a low pressure line G which may also receive steam from other lowpressure boilers such as B having drums D. Suitable burners areindicated at 36 receiving fuel from a line 33.

Referring now to Fig. 2, 1O designates the main supply tank for liquidfuel. A pump 14: withdraws the fuel from this tank and delivers it to asupplemental or auxiliary tank 15. From this supplemental tank fuel iswithdrawn by a pump 22 and delivered throu h a heating coil 31 disposedin the drum%) to a pipe or conduit 32. Conduit 32 leads to a controlvalve generally designated 32a. Under normal operating conditions theflow of liquid fuel through this valve is as shown, that is, from pipe32 to conduit 33. This conduit may be provided with a pressureindicating gauge 3-4 and a thermometer 35 to show the temperature of theoil. Conduit 33 extends to the burners generally designated 36. Theburners may be provided with control valves 37 so constructed that thefuel supplied to the burners will be cut off when the burners are swungout of their normal position. In this way the fuel is'automaticallyshutoff to a burner when this burner is swung out of the firebox orcombustion chamber C (Fig. 1) when brought out for inspection or repair.

Referring again to valve 32a, this valve is provided with valves 32b and320 which are so connected with the conduits 32 and 33 and 7 2a and 72that if the fuel flow through 32 is stopped, for example at 320 or 37, apassage is provided from point 30 to the tank 15 through conduit 72a,valve 326, loaded spring check or back pressure valve 73 and conduitGantrol devices Provision is made for giving a signal such as an audiblesignal to the operator in the event that the steam leaving the boilerreaches a'certain predetermined temperature. Such a condition wouldarise with certain types of boilers, that the quantity of fuel supplied,is greatly in excess of the water supplied. Such a condition would causean excessive superheating of the steam.

There is further provided means for automatically shutting off thesupply of fuel to the burners entirely in the event that the audiblesignal is disregarded and in the event that the steam temperatureattains a still higher or injurious limit.

Another control which is provided is a control for shutting off thesupply of fuel to the burners in the event that there is not a properair supply to the apparatus. A signal is also called into action in theevent that the fuel sup lied to the burners is shut off due to lack thatthe fuel control features of the present invention are not limited tooil fuels nor to the particular supply system herein described.

Referring again to Fig. 1, is one of the tube connections between suchsections of the boiler where a high temperature rise of the steamflowing therethrough would first be noticeable. This section 50 isprovided with a thermostat 51 of any desired form. Such thermostat ishere shown as comprising a tube of a material having a high thermalco-eflicient of expansion. Fastened to the upper end of this tube is arod 52 formed of a material with a different and lower thermalcoefiicient of expansion. Disposed adjacent rod 52 is a lever 53fulcrumed at 54 and carrying a screw 55 so as to be' adjustable in thelever with respect to rod 52. The lever 53 is normally spring pressed byan adj ustable spring 56 so that part 55 is kept in contact with rod 52and this spring 56 also. keeps lever 53in contact with its fulcrum. Oneend of lever 53 is provided with a lost motion forked connection 57which connection carries one of a pair of contacts 58 disposed in analarm circuit to audible signal 59. Upon'expansion of tube 51, contacts58 will close and cause audible signal 59 to sound. Upon a furthermovement of the fork 57 such fork will contact with a spring pressedlever 60 carrying on it valve 61. The normal position of valve 61 is asshown, but in the event of excessively high temperature conditions it isshifted to lower position to connect a conduit 62 to atmosphere throughport 63. 64 designates a suit.- able supply of compressed air. Thiscompressed air normally is in communication with conduit 62 throughconduits 65 and 66, valve 67 being in the position shown. Conduit 62 inturn leads through a two-way valve 68 to a cylinder 69. Within thecylinder is a plunger 70 which is provided with an adjustable spring 70a.. The plunger 70 is nor mally held inthe lower position as shown bythe pressure of the air from tank 64. However, upon the opening of 62 toatmosphere, valve 61 will shut off the air supply from the conduit 66and will release the pressure of the air within the cylinder 69.Thereupon plunger 70 will. move upwardly under the impulse of its springand shift valves 320 and 32?) from the position shown to upwardposition. By this action the fuel flowing through conduit 30 will bediverted into a conduit 72 and directed back to the supplementary supplytank. In this way the supply of fuel to the burners will be cut off. Toprevent the pressure on the fuel being wholly released, which mightcause volatilization of the fuel in coil 31 or in other parts of thesystem, a loaded valve 73 is provided to maintain a pressure upon thefuel irrespective of its 21111171113101). back to the supplementarysupply It will be understood that valve 73 is set for a relatively lowerpressure than that of the normal operating pressure of the burners.

When the pressure in'the system beyond the filters 28 (i. e. in 30, 31,32, 33, etc.) raises to an excessively high point which might occur forexample when all burners are shut ofi", this excessive pressure acts onthe area of valve 32?). This causes an opening of said valve as wellagainst the air pressure in chamber 69 and the oil then flows to tank 15through conduit 72.

For circulating and recirculating the oil to warm the fuel lines instarting up the plant, valves 32?) and 320 are in the position as shown.Hand operated valve 1 which is normally closed is, during the warming uptperi od, opened. The oil then circulates as lows: through heater 31,conduit 32, valve 320, conduits 33, 2, 3 and 72 back into tank 15.

The means for cutting off and diverting the fuel flow in the event offailure or insufficiency of air supply will now be described.

80 in Figs. 1 and 2 designates a pipe which leads to a gas duct of theboiler which is readily susceptible to changes in draft or air supply.With proper running conditions there will be a considerable vacuuminduced in pipe 80 which will maintain a diaphragm 81 in the positionshown and against the tension of spring 82. Upon a certain degree oflowering or complete failure of this vacuum diaphragm 81 will move tothe left under the influence of its spring and will actuate a leversystem generally designated 83. The details of this lever system aresubstantially the same as heretofore described in connection with valve61. Eventually movement of this lever system 83 will close contacts 84and cause the audible signal 59 to sound and this movement will alsoshift valve 67 from the position shown to an opposite position so thatthe compressed air supply from 65 will be shut off and so that conduit66 will be connected to atmosphere through port 85. The ultimate effectwill be the same as before, viz. that the fuel will be diverted from theburners back to the supplementary supply tank.

The control devices ]ust described are emergency devices. It is not theintention that these devices act as operating controls for the normalsupply of fuel to the burners. They are intended to come into action inthe event of inattention of the operator.

The control of the fuel sup ly in the event of improper air supply and te provision of the signal to indicate such improper air supply conditionand the shutting off of fuel forms the subject matter of my copendingapplication, Serial No. 280,195, filed May 24, 1928.

What I claim is:

A fuel burning system including means for controlling fuel supply,temperature controlled means, warmng means controlled by saidtemperature controlled means adapted for actuation upon a certaintemperature being reached to give a warning of an improper operatingCondition, and means also operative under the control of the temperaturecontrolled means when it attains a higher temperature than that whichinitiated the Warning to bring about operation of the fuel supplycontrolling means to shut off the fuel su ply.

n testimony whereof I hereunto aflix my signature.

KARL A.

